[PATCH] netfilter: ipset: Fix maximal range check in hash_ipportnet4_uadt()

Nathan Chancellor
2021-08-03T19:18:30Z

Clang warns:

net/netfilter/ipset/ip_set_hash_ipportnet.c:249:29: warning: variable
'port_to' is uninitialized when used here [-Wuninitialized]
if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
^~~~~~~
net/netfilter/ipset/ip_set_hash_ipportnet.c:167:45: note: initialize the
variable 'port_to' to silence this warning
u32 ip = 0, ip_to = 0, p = 0, port, port_to;
^
= 0
net/netfilter/ipset/ip_set_hash_ipportnet.c:249:39: warning: variable
'port' is uninitialized when used here [-Wuninitialized]
if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
^~~~
net/netfilter/ipset/ip_set_hash_ipportnet.c:167:36: note: initialize the
variable 'port' to silence this warning
u32 ip = 0, ip_to = 0, p = 0, port, port_to;
^
= 0
2 warnings generated.

The range check was added before port and port_to are initialized.
Shuffle the check after the initialization so that the check works
properly.

Fixes: 7fb6c63025ff ("netfilter: ipset: Limit the maximal range of consecutive elements to add/delete")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
net/netfilter/ipset/ip_set_hash_ipportnet.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/ipset/ip_set_hash_ipportnet.c b/net/netfilter/ipset/ip_set_hash_ipportnet.c
index b293aa1ff258..7df94f437f60 100644
--- a/net/netfilter/ipset/ip_set_hash_ipportnet.c
+++ b/net/netfilter/ipset/ip_set_hash_ipportnet.c
@@ -246,9 +246,6 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
ip_set_mask_from_to(ip, ip_to, cidr);
}

- if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
- return -ERANGE;
-
port_to = port = ntohs(e.port);
if (tb[IPSET_ATTR_PORT_TO]) {
port_to = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
@@ -256,6 +253,9 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
swap(port, port_to);
}

+ if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
+ return -ERANGE;
+
ip2_to = ip2_from;
if (tb[IPSET_ATTR_IP2_TO]) {
ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP2_TO], &ip2_to);

base-commit: 4d3fc8ead710a06c98d36f382777c6a843a83b7c
--
2.33.0.rc0